The "outside' is hypothetical, and assumes a (non-existent) additional dimension, and a (non-existent) observer with the ability to use that dimension to view the entire thing all at once.
Of course the "outside" is hypothetical. Maybe it is best called flat out imaginary. The "outside" goes along with or follows from the figurative "block" shape as a way of expressing thinking about occurrences occurring "within" the where-when "container" which is the spacetime universe.
Within the spacetime container, use can also made of the light cone shape to indicate a bit about where-when relative accessibilities, but the "all at once" is itself also an hypothetical with regards to the spacetime container. The all at once so as to be a static block is an assumption which might well have circumstantial utility (or maybe just convenience), but such utility would not be sufficient to establish the hypothesis as necessary; it would not be sufficient to establish that what is assumed is necessarily the case.
Obviously.
And this is where we get back to
the growing block notion stripped of the problem which results from its expression in terms of what "exists". In the suggested alternative growing block notion, there really is no need of an outside beyond that "outside" which (unfortunately?) follows from maintaining the inherited "block" descriptor.
Past and
present indicate spacetime container internal perspectives from which contents (occurrences) are set, fixed, utterly determinate so as to be devoid of any indeterminateness whatsoever whereas
future is a perspectival indicator of there being a not merely epistemic indeterminateness with regards to what occurrences/contents occur. This could be the case even if the "shape" of the spacetime container were to be utterly determinate/determined without being eternally, perpetually actual so as to be eternally, perpetually static.
All of which assumes absolute time - the existence of a "present" agreed upon by all observers, and (as a direct corollary) the fact that all observers agree on the sequence of events.
That assumption contradicts General Relativity, which seems like a very dangerous thing to do without some kind of evidence to justify doing it - GR is very well evidenced indeed, so to deny it requires a bit more than a feeling of unease about its implications, if we are interested in being reasonable about our conjectures.
The sole "evidence" that inspires the idea of replacing the static block with a growing block seems to be that the latter makes people uncomfortable.
Reality has no obligation to make anyone comfortable, nor to be easy or pleasant to contemplate.
As I understand it, there IS a present for all observers; but it looks different to all observers relative to their position in it, such that it is curved.
From every perspective the universe operates in a way distorted by the stuff at the perspective itself, such that for each of these
reference frames, none of them is
preferred.
As such, if you were to observe a "block space/time" of the universe, it would "distort as if looking through a strange lens" as you scrolled through and along it depending on the curvature of space and time at that point in it.
In my imagination, looking at a "time" would shift the size of a "bubble" from some hypothetical origin in or out.
To look at a different state, you would forward to a specific time beyond your interest, look back "at an angle in the cone", and see the point of that come from some other place later as it comes into view from your own current position... The conveniently treat its own evolution on from there?
It's really weird to think about trying to scroll through such an idea because it's so massive and weird and mechanical.
But assuming some theory of an aperiodic space relativity of continuity can happen with a deterministic block system, so long as causality actually continues in a locally real way.
There MIGHT even be some statistical limitations inherent to some such systems; I expect there WILL be statistical facts about such a thing that aren't directly apparent from the passage of time in the system, "spooky actions at distance".
Math has such weird and deep sorts of relationships going on "out around the back" as it were. But this still doesn't negate the relationship you see "around the front", as it were, either. The obvious relationship is still true with respect to the rules, but some systems have the weird statistical stuff, too.
That still doesn't change the facts about groups and permutations and representations that exist within the block of various relationships that occur due to those physical laws -- like the fact that statistically, you
cannot find an example of a thing progressing in some way that conflicts with its nature, AND that it's nature determines the contexts it can be seen progressing into and the new forms or versions it takes and the ways it takes them.
It seems like I can know, clear across an infinite universe what things "like me" are and aren't doing because of how "like me" they are or are not, that seems like a very powerful ability. It pierces beyond the event horizon of the universe, and possibly even across event horizons into whole other mathematical concepts merely using the power of a brain to simulate and re-order stuff until it behaves in some symmetry with some other
concept of stuff, so as to represent the preferred function.
One issue, however, is that the static block isn't distinct from a growing block when discussing the block.
If you wanted to conceptualize a growing block, you would instead start with each point-location in space and time like a column or tube. At each moment, you would drop a dice to the bottom, and it would reveal a number to every side. The position and orientation of the "dice" then determines how each of the neighbors interacts with it, of the ways it's current state can interact, and each tower looks downward in a cone from the topmost dice to see how those towers interact: from the perspective of "now", it looks like stuff everywhere has been fixed for a while out to the edge of the cone, but that's just because you can't see the next dice rolling down, on you or anywhere.
In the end, it can be replayed as a block using the same dice rolls, but the dice rolls and this the result would be different every time...
... But the block it produces once it's resolved through the addition of the driving information is still "static", and so "growing" block time is less a description of the block time and more a description of what exactly you did to generate it.
While the truth of the statistical relationships hold among it with regards to causality, it exists to observe and know and infer its rules by the truths that hold across it same as anything in it might. An observer of the block interested in the rules across it but unsure of them because to them it is a block, may find out those rules by finding things such as us in there that operated scientifically and rationally and reverse engineered aspects of the block even as parts of it enough to build their own simpler model blocks within the block and infer that it is a block governed by causal framing and local realism and so on.
It could literally be that our reality is a big crystal just growing on the underside of a very weirdly shaped rock, which would comport to this idea of "growing block spacetime", and the parts of it would still be responsible as what they were for acting as the banks which control the chaotic flow of the river.
bigthink.com
